trace tcp_output.c:1772
  commands
    collect $reg
  end
disable
trace /home/teawater/big/kernel/tb/32/linux-2.6.32-131.2.1.el6/net/ipv4/tcp_output.c:1748
  commands
    collect ((struct tcp_sock *)sk)->rx_opt.rcv_wscale
    collect ((struct tcp_sock *)sk)->rcv_ssthresh
    collect ((struct tcp_sock *)sk)->rcv_wnd
    collect sk->sk_rcvbuf
    collect sk->sk_rmem_alloc
    collect window
  end

define showall
    p ((struct tcp_sock *)sk)->rx_opt.rcv_wscale
    p ((struct tcp_sock *)sk)->rcv_ssthresh
    p ((struct tcp_sock *)sk)->rcv_wnd
    p sk->sk_rcvbuf
    p sk->sk_rmem_alloc
    p window
    p (window >> ((struct tcp_sock *)sk)->rx_opt.rcv_wscale)<<((struct tcp_sock *)sk)->rx_opt.rcv_wscale
    p ((window >> ((struct tcp_sock *)sk)->rx_opt.rcv_wscale) + 1)<< ((struct tcp_sock *)sk)->rx_opt.rcv_wscale
  end